Machine for applying specular coatings



Oct. 2, 1951 J. H. GREEN MACHINE FOR APPLYING SPECULAR COATINGS 6Sheets-Sheet 1 Filed NOV. 27, 1948 INVENTOR.

W TVIZNEY.

Oct. 2, 1951 GREEN 2,569,852

MACHINE FOR APPLYING SPECULAR COATINGS Filed Nov. 27, 1948 6Sheets-Sheet 2 Jim/Pm? F/mu Ear/Muir WITNE55E5 V v INVENTOR 159 7. H.GEE EN I BY? B 1,95 1 w W 1K7 154 ATTORNEY Oct. 2, 1951 J. H. GREENMACHINE FOR APPLYING SPECULAR COATINGS 6 Sheets-Sheet 5 Filed Nov. 27,1948 dram/wily U INVENTOR J b. G'FfE/V.

Yfl MW farm/wavy WITNESSES ATTQRNEY Oct. 2, 1951 J. H. GREEN MACHINE FORAPPLYING SPECULAR COATINGS 6 Sheets-Sheet 4 Filed NOV. 27, 1948 INVENTORJ: H G'FEE/V 5 WITNESSES:

ATTORNEY JOWK m-4, @169; M

Oct. 2, 1951 J. H. GREEN v MACHINE FOR APPLYING SPECULAR COATINGS 6Sheets-Sheet 5 Filed NOV. 2'7, 1948 ATTORN EY J? A. GE'EEAL WITNESSESOct. 2, 19-51 J. H. GREEN MACHINE FOR APPLYING SPECULAR COATINGS FiledNOV. 27, 1948 WITNESSES:

( Wa g 6 Sheets-Sheet 6 INVEINTOR J: h. GREEN W A mm ATTORNEY Patented2, 1951' MACHINE FOR APPLYING SPECULAR COATINGS James H. Green, WestOrange, N. J., assignor to Westinghouse Electric Corporation, EastPittsburgh, Pa., a corporation of Pennsylvania Application November 27,1948, Serial No. 62,343

11 Claims. 1

This application is a continuation-in-part of my copending applicationSerial No. 671,545, flled May 22, 1946, now abandoned, and entitledMethod and Apparatus for Applying Specular Coatings.

This invention relates to coating the interior surfaces of transparentvitreous envelopes with specular material, such as aluminum.

The principal object of my invention, generally considered, is tomanufacture bulbs for heat, spot, flood, and sun lamps, and otherdevices in which radiant energy is to be reflected therefrom in acertain direction, by applying a specular coating of a metal, such asaluminum, for example, over a portion only of such bulbs, the remainderbeing kept clear to allow the radiant energy to freely emerge therefrom.

Another object of my invention is to coat bulbs for radiant energydevices with reflecting material, while portions thereof are coveredwith a suitable masking material to leave a translucent or transparentwindow in each bulb to thereby allow for the transmission of radiantenergy in a desired direction.

A further object of my invention is to provide a machine forautomatically adjusting the masking-material in the bulb, evacuating,flashing the specular material on the unmasked portion of the bulb, andunloading the coated bulb from the machine.

Other objects and advantages of the invention will become apparent asthe description proceeds.

In the drawing:

Figure 1 is an elevational view, partlyin axial section, of a lamp of atype manufactured in accordance with my invention. a

Figure 2 is a side elevational view, partly in section, of a bulb usedto make a lamp of a type similar to that illustrated in Figure 1 duringthe process of rotation to distribute masking material being fedthereto, as desired, over the end to be kept clear of a reflectingcoating.

Figure 3 is an elevational view, partly in vertical section, ofapparatus for evacuating a lamp bulb and flashing a reflecting coatingthereon.

Figure 4 shows the masking material being poured out of a bulb after ithas been removed a specular material may be vaporized onto a bulb, inaccordance with my invention.

Figure 9 is a vertical sectional view on the line IX-JX of Figure '7, inthe direction of the arrows.

Figure 10 is an elevational view of a doubleacting pinch valve forcontrolling the exhausting of bulbs in accordance with my invention,said valve being shown in open position, and a valve actuator on themachine being shown ready to move said valve to closed position, atposition 2| on the machine.

Figure 11 is an elevational view of a similar valve illustrated inclosed position, and a valve actuator of the machine being shownassociated therewith in a position about to open said valve, also atposition 2|.

Figure 12 is an elevational view of three of the valves for controllingthe exhausting of bulbs, in accordance with my invention, on the lines)HI-XII of Figs. 7 and 9, in the direction of the arrows, associatedapparatus being illustrated whereby the final exhaust is not applied ifthe preliminary exhaust valve has been manually or otherwise closedprior to a prospective change over from preliminary to final exhaust.

Figure 13 is a fragmentary sectional view on the line XIII-XIII ofFigure 12, in the direction of the arrows.

Figure 14 is a fragmentary elevational view. with a part in section onthe line XIV-XIV of Figure 12, in the direction of the arrows.

Figure 15 is an elevational view of a portion of the apparatus, showinghow the masking material is applied to the bulbs, how it is distributed,and how the coated bulbs are finally removed from the machine.

Figure 16 is a fragmentary plan, with parts in section on the lineXVI-XVI of Figure 15.

Figure 17 is an elevational view, with parts in section on the lineXVII-XVII of, Figure 15, in the direction of the arrows.

Figure 18 is a fragmentary view of a finished bulb as it is dischargedfrom the machine, and a detailed sectional view of a. device forreceiving such a bulb, shown supported thereon, said device being shownin bulb-receiving position.

Figure 19 is a detailed sectional view, corresponding to Figure 18 butshowing the device after the bulb holder thereof has been tipped todischarge the bulb from the machine.

In the previous manufacture of reflecting bulbs, for devices such asinfra-red lamps and sunlamps, it has been the practice to flash specularmaterial, such as aluminum, on the inner surface of the bulb and thendissolve a portion of said coating. so as to form a translucent ortransparent window for the radiant energy to be distributed therefrom.

The purpose of my invention is to apply such a coating to the portion ofeach bulb as desired, leaving the remainder uncovered for thetransmission of radiant energy, and thereby avoid the necessity fordissolving a portion of the coating after application.

' Form of Figures 1 to 5, inclusive Referring to the drawing in detail,like parts being designated by like reference characters, and firstconsidering the embodiment of my invention illustrated in Figures 1 to5, inclusive, there is shown in Figure l, a lamp l comprising anenvelope or bulb i-l closed bya press l2 carrying an energy translatingfilament or other device i3, and having a base i4 which may bescrewthreaded. The base-adjacent portion of the bulb is shown coveredwith a reflecting coating I5 on the inside thereof, which coating may beof aluminum or other specular material, preferably metal, flashed orvaporized thereon in a manner which will now be explained. The portionI6 of the bulb opposite the base is either clear or frosted, as desired.

' In practicing the process, I first take an open necked glass bulb orenvelope H, such as shown in Figure l, or modified, if desired, as shownin Figure 2, and invert it as compared with its position in Figure l. Ameasured quantity i! of masking material, such an Aiundum powder, flneglass granules, or other heavy, fine, preferably non-metallic powder, orgranular material is then poured therein, as from a receptacle i8 orother bulb. The powder H, which is desirably, although not necessarilywhat is called Barium Crown Glass Beads," preferably .014" in diameter,and between the limits of .014" and .017", as manufactured by PotterBros. of Long Island, may be distributed in any desired manner,preferably while being poured, by having the bulb ii on a support I9and, while the neck 2| is held by means 22 upright but unrestrainedagainst rotation, the support I9 is rotated or oscillated by any desiredmeans, such as a pulley 23 on a shaft 24 therefrom. The pulley isoperated, as by a belt 25 from a motor, not shown, so that the powder ITis evenly distributed on the bottom, as desired, by centrifugal force toa predetermined cutoff line.

Referring now to Figure 3 there is shown evacuating apparatus 26 whichmay consistof a manifold 21, only a fragmentary portion of which isshown, each portion comprisin a head or cham ber 28 opening downwardlyand carrying means for making an airtight connection with a bulb, suchas a soft rubber mouthpiece 29. The mouthpiece is closed by elevating amasking-materialcontaining bulb Ii, from the dotted position to thefull-line position, as by means of a platform or support 3| from whichrack bar 32 depends. The rack bar is engaged by pinion 33 which may beoperated manually by crank 34 and handle 35, and passes through a tableor other support 36. Other means of elevating bulb H may be substitutedif desired, such as air, motor or hydraulic cylinders.

Each chamber 23 also desirably has electrodes 31 and 33, between whichmay be mounted a container coil 39 of refractory metal wire such astungsten, molybdenum, or similar material. In said coil is a desiredquantity of specular material to be flashed on the bulb ll, such as oneor more pieces 4i of aluminum sheet or wire. A deiii! sirable materialis crimped aluminum ribbon, preferably that designated by the assigneeas #3. As an alternative, the coil 39 may be replaced by a pot orcontainer for the specular material, in turn enclosed in a highfrequency induction coil for creating the desired heating effect. Theflla- Y ment may be heated to flash the specular material onto theuncovered inner surface of the bulb, as by means of a variabletransformer 42. The primary winding .43 is energized from the source ofpower 44 through switch 45, and the secondary winding 46 is connected toone of the electrodes, such as 38, by means of conductor 48. Saidelectrode 38 is electrically separated from the manifold 21 byinsulating or glass cylinder 41. A voltmeter 49 is desirably used toshow the applied potential. The other side of the line may be groundedat 5|, and the electrode 31 electrically connected to the manifold 21,grounded as indicated at 52.

Operation, referring to Figure 3 The manifold 21' and connected bulbs iiare evacuated, flrst roughly through valve 53 connectedgby pipe 54 tovacuum pump, such as one of the Kinney type designated 55. Desirablyduring the time gas is being removed from bulb II by Kinney pump 55, theradio-frequency coil is energized from an oscillator 86 for the purposeof ionizing said gas, thereby bombarding the inner surface of theenvelope to get rid of moisture and occluded gases. At a predeterminedperiod in this evacuation when the ionization has been reduced to aminimum, valve 53 is closed and valve 56 opened to finally evacuate themanifold and bulbs II, as by means of an oil diffusion pump 51, whichmay be one of the type designated VMF20 and manufactured by DistillationProducts, Inc., 570 Lexington Ave., New York city 22, N. Y., and Kinneypump 55'. When a pressure of about 1 micron is reached, as shown by 9.micron or Pirani gauge 59 connected through a switch 6i to the source ofpower 44, the switch may be closed, while the transformer is adjusted tocause the coil 39 to first heat and slightly melt the aluminum, or othermaterial 4| held therein, onto the supporting wire 39 in the envelope H.

The purpose of first slightly melting the aluminum, or other material tobe applied to the bulb,

is to avoid an explosive flash which might damage the bulb and/or causethe coating material to be deposited non-uniformly thereon. After thiscoating material has been melted slightly, and before it has had achance to run off the supporting wire, it is allowed to solidify on saidwire. Then the transformer is adjusted to a higher voltage, the switch45 is again closed, at this time vaporizing the aluminum or othercoating material from the wire 39 to which it has adhered. Thevaporization is thereby effected quickly but uniformly upon theuncovered surface of the envelope or bulb. It is essential that flashingof the coating material be of long enough duration to remove all of itfrom the heating coil.

Although only one envelope is illustrated, it will be understood thatthe evacuation of any convenient number of envelopes may besimultaneously effected and all of said envelopes coated simultaneously,or at about the same time, by flashing aluminum or other materialthereon. In coating a series of envelopes, for example six, it isdesirable to first apply approximately /2 voltage to the filaments inthe envelopes. as by connecting adjacent pairs in series so that thealuminum, or other coating material, is first melted in the first pair,then in the second pair, and finally in the third pair, while thematerial in the preceding pair, or pairs. is allowed to cool. Thevoltage is then increased, as by changing the connections to similarlysuccessively flash the pairs of filaments in the bulbs in parallelinstead of series, thereby vaporizing the coating material upon thebulbs of the first pair, then upon the bulbsof the second pair, andfinally upon the bulbs of the third pair.

After the coating operation has been effected, the apparatus is allowedto cool and the valve 6! opened to break the vacuum. The envelope I land the other envelopes on the manifold 21 are then removed, and theAlundum or other material poured out, as illustrated in Figure 4, intoanother envelope, or if the masking material is to be tested, as is doneat infrequent intervals, into a receptacle 33.

Embodiment of Figure 6 Referring now to the embodiment of my inventionillustrated by the wiring diagram of Figure 6, there is shown a switch94 connecting an adjustable auto-transformer 65 with a source of powerwhich may be 110 volt, 60 cycle A. 0., represented by terminals 66 and61, through fuses i8 and 69 or other circuit-breaking means. Theauto-transformer is connected to the primary winding ll of transformer12, through line I3 connected to one pole of the auto-transformer I5 andthrough fused line 13 connected to the adjusting terminal I5 of saidauto transformer 85.

The secondary winding 16 of said transformer 12 is connected tochange-over switch 11 which is for the purpose of changing theconnection to the filaments 39 and 39". These filaments are onlydiagrammatically illustrated, but are supposed to be mounted in bulbsand carry aluminum or other specular material like the filament 39 inFigure 3. The filament 39, although shown as a single filament, mayrepresent two or more filaments in parallel, each filament being mountedin its separate envelope, like the filament 39 in Figure 3, and asimilar comment applies to the filament 39', although the operation isdesirably as shown in Figure 3.

In using the apparatus illustrated in Figure 6, the switch 64 is firstclosed when the'switch TI is in a position as shown in full lines. Theautotransformer contact is adjusted to give the desired voltage in thesecondary winding 18 when the circuit is closed through the filaments 39and 39". These filaments are first energized with the switch 'll in theposition shown in full lines, so that the current flows from saidsecondary winding 16 through line 19, switch element 19, filament 39,line 8|, filament 39. switch element 32, and back to secondary winding16 through line 33. This, of course, means that the filaments are firstenergized at half voltage or in series, so that the aluminum or coatingmaterial is merely melted.

If the pair of filaments, 39 and 39', represents only one unit of aseries, as previously described broadly, then the next pair of filamentsmay be energized in the same manner through a similar arrangement, whilethe filaments 39 and 39 are allowed to cool. Finally, after all of saidfilaments have been so treated, or if there are no other filaments inthe series after a pro-determined short-time interval allowing thecoating material to cool, the switch 11 is moved from the This secondenergization of the filament at full voltage vaporizes the aluminum orother coating material thereon and effects the desired coating of theenclosing bulbs. This vaporization in the bulbs carrying the filaments39 and 39, if merely a unit of a series may be followed by vaporizationof the coating material carried by the filaments in successive pairs ofbulbs, as was done in connection with the initial treatment of suchfilaments.

From the foregoing disclosure it will be seen that I have devised animproved method and apparatus for aluminizing bulbs, and particularlythose of the R40 Sunlamp type. Although only a portion of the manifoldis illustrated, it will be understood that it may involve six heads. Twoor more of such manifolds may, if desired, be used on a single table orother support. The valves 53 and 58 may be of the hand operated on-ofitype, and the valve 62 is a simple airrelease valve. Under the invertedheads, the platform 3| raises and lowers for loading and unloading thebulbs. Although the drawing shows means for merely heating the coil 39by the resistance thereof, it will be understood that high-frequency orradio-frequency power may be substituted for mere alternating or directcurrent, so that the metal used as a coating material may be inductivelyheated.

By my invention I have accomplished various results, as compared withthe prior method of coating the entire bulb and then dissolving aportion thereof of the reflecting surface. One is the improvement inquality in connection with Sunlamp manufacture insuring at least aincrease in ultraviolet output. A further improvement is that, whenusing radio-frequency as the ionizing means, the pumping time per loadis reduced from 5 minutes to 3 minutes, or only of the normal pumpingtime is required. A further gain is an improvement in the hardness andadherence of the specular coating, and the improvement in its appearanceby having a sawtoothed edge, the fineness of which depends on the sizeof the grains of masking material, rather than one which is unwavering.By using Alundum, a fine grain emery, or similar granular substance asthe masking agent, four operations which existed in the previousmanufacturing procedure have been eliminated, that is (1) the water washahead of the dissolving operation, (2) the dissolving of the metalcoating on the bulb ends, (3) the after wash to neutralize thedissolving acids used, and (4) a baking operation to dry the bulbs.

Embodiment of Figures 7 to 19 Referring now to the embodiment of myinvention illustrated in Figures 7 to 19, inclusive, there is shown arotary conveyor 81 so constructed that it automatically aluminizes andthen discharges finished bulbs. An associated rotary bulbpreparingmachine or turret 88 is employed to load and level the masking materialin each bulb to be aluminized. The machine 33 is driven from the samesource of power as that which drives the conveyor 81. It distributes themasking material so as to insure that the deposit of the aluminum is cutoil or stopped at a desired plane. From this machine 88, the bulbs aretransferred manually by the first operator, one at a time to theconveyor 81 which carries out the entire aluminizing operation, andfinally at a point of near tangency between the circle of movement ofbulbs on the conveyor and the circle of movement of bulbs on the turret,empties the masking material into another bulb, which is then preparedfor in a similar manner for aluminizing. The only other manualoperations are those of placing the aluminum, or other specularmaterial89, in the flashing filament 9I, which is desirably a coil of tungsten,prior to placing the loaded bulb on the machine, and packing thealuminized bulbs, as they are discharged from the machine and inspected,in a suitable receptacle. Before describing the operation of the machinein detail, I will first describe the various parts thereof and themanner in which they operate.

The conveyor The conveyor81 comprises a base 92 on which is mounted apedestal 93. Secured to said pedestal 93 is a generally circularplatform member 94 serving as a support for various parts of the machinewhich will subsequently be described. On this platform member rests agenerally annular supporting device 95, providing an annular tray 96, inwhich rest the manifolds 91, from which exhaust lines or pipes 98, 99,and IOI extend to the lower member I02 of valve I03 for connecting thevarious exhaust lines to the various heads I04 of the machine insequence. this lower valve member I02 rests the upper member I05 of thevalve I03, which moves with the rotary portion or spider I06 of theconveyor 81. The spider I06 comprises a central portion t 01, secured toan upright hollow drive shaft I08, and a main or body portion I09 towhich a plurality of brackets III, in this instance twenty-four, aresecured. Each bracket carries a device or head I04 for air-tightevacuating connection to, and deposition of coating material on, a bulbbeing processed.

f The shaft I00 carries at its lower end a gear H2 formed by a series ofpivotally-mounted rustoconical rollers II3, successively engaged by thedrive wheel I I4 on shaft IIS, which is driven from motor I I6, throughbelt II1 over pulley II8 mounted on shaft II9 which carries worm (notshown) meshing with worm wheel I2I secured on shaft I I5. The drivewheel I I4 is so formed that, as it turns, the gear H2 is keptstationary for the greater part of its revolution, but moves a step,that is, from one indexed position to the next, as an engaged roller II3passes along the axially-curved trough portion I22 which joins theaxially-oifset trough portions I and I30, as shown in Figure '1, wherebyeach head I04 of the machine is indexed in one position for a certainlength of time and then promptly moved to its next indexed position.

Bulb-preparing turret The bulb-preparing machine or turret 8B is drivenstep by step, so that it indexes like the conveyor 81, by means of a camI23 on the shaft I I5, which cam engages a roller I24 on a lever I25secured by a pivot at I26 to a bracket I21 upstanding from the base 92of the machine. The roller I24 is kept in engagement with the cam I23 bya coil 8 spring 90 acting between a bracket I00 on the other end of saidlever and a bracket IIO on the base 92. Said other end of the lever I25carries a pin I28 received in a slot I29 of the arm I3I of a bell-cranklever I32, connected by pivot pin I33 to base member I34 ofbulb-preparing machine 88, which is in turn secured to base 92 as bybolts I35. The other arm I36 of bell crank lever I32 is connectedthrough a pivot pin I31, rod I38, and pin I39, to lever I4I, pivotedabout the main upright shaft I42 of bulb-preparing machine 88.

The shaft I42 carries a spider I43, comprising a column portion I44through which the shaft I42 extends, and about which the spider rotates,and an annular platform portion carrying adjacent its periphery a seriesof rotatable shafts I46, on the top of each of which is mounted a bulbsupporting member I41. Between the bulb-supporting members and theplatform portion I45 are anti-friction means I48, such as rollers orball bearings. The lower end of each shaft I46 carries a pinion I49secured thereto, as by means of a pin I5I. Mounted on the upper end ofthe column I44, is a disc I52 carrying a series of plates I53, each ofwhich is notched as indicated at I54, so that when a bulb I55 rests on abulb-. supporting member I41, its neck may be disposed in the notch ofthe member I53 immediately thereabove, to insure that it is in a desiredvertical position.

Step-by-step indexing motion of the spider I" is efiectecl by a ratchetI56 secured to the .bottom thereof, as by means of bolts I51, andengaged by a pawl I58 carried by the 1ever I4I, whereby movement of thelever back and forth effects indexing of the spider from one position tothe next, in this instance, through V of a revolution, as the spider isformed to support eight bulbs. As will be understood, the ratchet I56has the same number of teeth as the spider has bulb-supporting portions.

In order to effect a twirling movement of each bulb, after being loadedwith masking material I59, sufficiently fast so that said maskingmaterial is distributed to a uniform cut-off plane, the pinions I49 aresequentially engaged by a gear segment I6I, pivoted about the shaft I42,and oscillated. This is effected by having an arm I62 on the segmenti6I, connected by a flexible cable I63, passing through a guide to apivot pin I65 in arm I66 of hell crank lever I61 pivoted to standard I68extending from the base 92, by connecting pin I69. The other arm I1I ofsaid lever I61 carries a roller I12 pivoted at I13 and held inengagement with a cam I14 by means of coil spring I15 acting between thearm HI and bracket I10 on standard I68. By virtueof the shape of the camI14. as each pinion I49 comes into engagement with the gear segment I6'Ias the spider I43 is indexed, the correspondingbulb support I41 isrotated back and forth twice about the axis of the bulb neck, therebydistributing the measured quantity of masking material I59 to a uniformcut-off level, as illustrated.

Flash-timing mechanism The shaft II5 also carries a gear I16, over whichpasses a chain I11 meshing with a corresponding gear I18 on a shaft I19carrying a series of timing cams I8I, I82, and I83, respectively engagedby rollers I84 of timing switch elements I85. These cams I8I, I82,-andI83,only the second one of which is shown in detail in Figure 8, areadjustable as there indicated by each being formed of tworelatively-rotatable cam segments I and I01, held in adjustablerelationship by bolt I 88, so that the proportion of each revolutionthat the actuated switch member I85 is held against the cooperatingswitch member I09, may be regulated so that the filament 3| is energizedfor a desired length of time for flashing the enclosed specular material09 therefrom.

A typical flashing circuit, representing circuit #2 at position I1,is,illustrated in Figure 8, comprising an adjustable auto-transformerISI energized from a power circuit I02, through switch I93, and in turnenergizing the primary winding I04 01 transformer I 95, the secondarywinding I 30 of said transformer being connected to one of the leads I31of a head I04, as said head is indexed at one of the positions I 0, I1,or III as shown in Figure 7, as by means of aflexible s1ipcontact memberI00, the other lead I 93 being rounded as indicated at 20I. The otherterminal of the secondary winding is grounded as indicated at 202, and avoltmeter 203 is disposed across the secondary-winding terminals so asto indicate the voltage adjustment.

Although I have shown three flashing positions, it is ordinarilyunnecessary to use more than two, the third position being a standby anddisconnected. The auto-transformer I9I is so adjusted that voltage atthe first flashing position, numbered I6, is just suflicient to softenor barely melt the aluminum 8!, whereby it closely rests in consolidatedcondition on the flashing coil BI, ready to be vaporized at the nextposition, or that designated I1. It has been found in practice thatabout 4 or 5 volts may be applied to effect this softening or melting ofthe aluminum, while about to 10.5 volts is needed for the flashingoperation at position I1.

Evacuating system The evacuating means, desirably a plurality of pumpssuch as those of the Kinney type, are connected to the exhaust manifolds91 in any desired manner, and from there the vacuum system is lead tothe outer exhaust pipes 204 and the inner exhaust pipes 205, both ofwhich connect with the exhausting heads I04. In the present machine,there are in general two types of vacuum pipes, that is, those whichform the preliminary evacuating system, and those which form the finalevacuating system. The preliminary evacuating means is connected to theinner of the exhaust manifolds 91, and from there controlled by theinner passages of the valve members I02 and I 05, through the outerexhaust pipes 204, which connect-with the outer portions of the heads I04.

The final evacuating means is connected to the outer of the exhaustmanifolds and from there controlled by the outer passages in the valvemembers I02 and I05, through the inner exhaust pipes 205, in series withsupplemental evacuating means, which in the present embodiment comprisesoil diffusion pumps 206 which may be of the type VMF previously referredto. These pumps as illustrated, receive electric power throughconductors I40 and I50, connecting through flexible contacts with sliprings I60 and I10, mounted on an insulating portion of the tray 35 andconnected to a suitable source. A cooling system through which watercirculates is provided for each pump 200 from supply pipe 208 tomanifold 209, from whence it passes through pipe 201 to manifold 2I I,from whence it passes out through pipe 2 I 2.

A consideration of Figure 7 will show that the val loaded bulb I55. areceived from the bulb-preparing machine 00, are fed to the conveyor 01at a position such as that designated '23 or that designated 24, wherethe exhausting begins. A desirable way to start the preliminary exhaustis by means of a so-cailed megavac pump or house rough vacuum system,with plug constrictions in the connecting pipes so as to avoid initiallydestroying the vacuum in the system to too great an extent. A Kinneypump or pumps may, however, serve for preliminary evacuating, and suchpump or pumps may be employed to, through the inner passages in thevalve members I02 and I05, draw the air from the heads I04 to which thebulbs I are connected as shown in detail in Figure 8. A soft rubberfacing 2I3 is used at each head to seal its engagement with theassociated bulb.

This preliminary exhaust connection continues through position 1, asshown in Figure 7, whereupon at position 8 each bulb is successivelyswitched on to final exhaust through the outer passages of the valveI03, making use of the diffusion pumps 206 and the inner exhaust pipes205.

Pinch valves The pipes 204 and 205 are respectively controlled by portclosers in the form of pinch valves 2I4 and 2I5, making two valves perhead I04, as shown in detail in Figures 10, 11, and 12. These valves maybe identical, but the valves 2 I4 for controlling the preliminaryexhaust, shown in detail in Figure 11 and at the extreme right and leftof Figure 12, are positioned on a circle of greater radius than thevalves 2I5 for controlling the final exhaust, shown in detail in Figure10 and as the middle valve of Figure 12, so that they are operated bydifferent stops or roller cams on the machine. A consideration of thesefigures will show that each valve comprises a body casting 2I6, throughwhich a flexible rubber vacuum hose 2I1 passes. The closing of the hose2I1 is eflfected by a valve plate 2I8 pivoted at 2 I9, and controlled bya closing lever 22I, pivoted at 222, and having a short angularextension 223 carrying a roller 224 which engages the top surface of'theplate 2I8. As the lever MI is moved from the position shown in Figure 10to that shown in Figure 11, as by a cam or stop 225 at position 2I onthe machine, the plate 2I0 is moved down to compress the rubber hose2I1, thereby closing the aperture therethrough and holding it in acompressed position.

The opening lever 226 of each valve is pivoted to the body casting 2I6as at 221, and has a short extension 228 pivoted to a connecting rod220, the other end of which is in turn pivoted to an intermediateportion of a prying member 23I carrying a roller 232, and connected withthe body casting 2I6 by a pivot member 233. When the opening lever 226is moved to the left, that is, from the position of Figure 11 to that ofFigure 10, as by engagement of astationary member or roller cam 234therewith at position 2| during rotation of the conveyor 81, the pryingmember aeeaess or roller cam 236, almost simultaneously but immediatelythereafter opening the corresponding inner valve 215.

In order to take care of a situation where a head may not have aconnected bulb 155, or where a connected bulb may have become broken dueto the evacuating operationor for any reason, or where the operator forthis or any other reason may have manually closed a valve 214,orprovision is made for automatically closing such a valve upon thedevelopment of a leak, thereby preventing the pumping of a bulb, if inthe corresponding head, or because a preliminary valve 214 was closed inorder to prevent waste of power due to the absence or breakage of a bulbin said head, I provide means for automatically insuring that the finalvacuum connection is not made. These means involve a feeler member 231on reciprocating rod 238, moved by a cam 239 on shaft 115 (Figs. '1, 9and 12). The cam 239 engages a roller 241 on an arm 242 of a crank 249carried by a shaft 243, rotatable in a bracket 244 mounted on the base92. The roller 241 is held in engagement with said cam 239 by a coilspring 245 acting between an arm 246 of said crank and a bracket 241 onthe base 92.

This cam 239 thus causes the shaft 243 to oscillate and, through a crank249 thereon, move a connected rod 249 with its arm 252 up and down in abracket 251 carried by the platform member 94. The arm 252 slides on rod238 against the action of light coil spring 253 thereon held betweensaid arm 252 and a stop collar 254 on said rod. The coil spring 253tends to push the collar 254 and connected rod 238 down,- so that thearm 255 mounted adjacent the top of the rod 238, and carrying anadjustable set screw 256, is caused to engage the top of the arm 252 asshown in Figure 12.

A mercury switch 251 in circuit with a solenoid 258, controlling theroller cam 236, and biased slightly toward open position by a light coilspring 259, is connected by a pivot 26! to a bracket 262 supported bythe bracket 251, and provided with an arm 263 underlying the set screw256. If on reciprocation of the rod 231 the feeler 238 finds the closinglever 221 closed, rather than in the normal open position represented inFigure 12, it will move down a relatively great distance, rather thanthe small distance indicated by the arrow 264, and cause the set screw256 to engage the arm 263, and effect closure of the mercury switch 251,energization of the/solenoid 258, and consequent raising thereby of theroller cam 236, through the distance represented by the arrow 269. Thisprevents engagement of said cam 236 with the opening lever 226 of thecorresponding valve 215 to the final vacuum system.

Thus, if one of the valves 214 has been closed for any reason prior toreaching position 1, the feeler 231 will move downwardly a greaterdistance than that represented by the arrow 264, or one sufficient toeffect closure of the mercury switch 251, thereby raising the cam 236'toits upper position in order to avoid opening the corresponding valve215. This means that the mercury switch 251 has been movedcounterclockwise, as represented in Figure 14, to closed posi-' tion.Because the spring 259 i very light, the switch would tend to stay inthat position, thereby preventing desired opening of subsequent valves215 and initiation of the final exhaust, even though the next valve 214is in open or normal position. I

In order to avoid such an undesirable situation, I provide a roller cam169 disposed a slight distance counterclockwise beyond. but on the samecircumference as the cam 236. This cam 199 is pivoted to a lever 199, inturn pivoted to a bracket 299 and adapted to roll over the upper face ofeach lever 221, in the closed position represented in Figure 12.Engaging the top of this cam is a rod 219 reciprocating in the bracket299 and carrying an arm 219 near its upper end. The rod 219 also carriesan outstanding post 229 connected by a coil spring 239 to acorresponding post 269 on the bracket, whereby said rod is urgeddownwardly into engagement with the roller 169.

The arm 219 carries a set screw 299 locked in adjusted position by a nut399. The mercury switch device 261 carries an arm 391 normally overlyingthe set screw 299, as shown diagrammatically in Figure 14, so that ifthe mercury switch 261 is closed as the roller 1811 is engaged by thelever 221, the rod 219 as it is pushed upwardly causes the set screw 289to engage the arm 391 and, assisted by the coil spring 259, trips themercury switch back to normally-open position as in Figure 14.

The high frequency control At positions 4 and 5, or at such positionswhere the pumps have reduced the pressure in the bulbs being evacuatedto between 25 and '15 microns of mercury, I may provide high-frequencycoils 265 and 266 carried in an enclosure 261 which is moved up tosurround the bulbs 166 to be aluminized as they are indexed, and moveddown out of the way to clear the bulbs while they are being moved fromone position to the next. The moving means for this control comprises alever-263 pivoted about the shaft 243 and its outer end moving the highfrequency coils up and down, while its inner end carries a roller 266engaging a cam 211 mounted on shaft 1 15, whereby the movement of thelever is synchronized with the indexing of the heads 194.- Thecoilmoving means desirably includes a switch for energizing the coils265 and 266 only when they surround indexed bulbs. The frequency of theenergizing power is desirably between kilocycles and 30 megacycles.

Unloading of bulbs Figures 15 to 19, inclusive, show details of theapparatus which acts to receive each bulb 156, as the vacuum thereto isbroken after the aluminizing is complete, and discharge it into a chute212, from which it is removed by the operator preparatory to being used,as for making a lamp. This apparatus involves a bulb holder 213,connected by a pivot pin 214 to a terminal casting 215, carried by apair of rods 216 which reciprocate in bracket 211 mounted on base 92.Reciprocation is effected by a connection with the end of the lever 125,through link 218 and connecting pivot 219, to a crosshead 261 to whichthe lower ends of the rods 216 are secured, by means of pivot pin 282.

In order to adjust the normal position of the bulb holder 213, a setscrew 283 is provided extending from the casting 215 to the bottom faceof the holder 213, and locked in adjusted position by nut 284. Tiltingof the bulb holder 213, to the unloading dotted-line positionrepresented in Figure 15, is efiected by a post 285 carried by thebracket 211 and upstanding between the reciprocating rods 216, so thatas said rods descend amass:

13' carrying the'holder 278 therewith, the' roller 288 mounted on thetop of the rod 285 engages the cam surface 281 on the bulb holder 218,and tilts the latter to upset and discharge the bulb I55 carried thereoninto the chute 212.

A gate 288 in said chute is provided to automatically stop each bulb I55as it i received, and release it prior to reception of the next bulb..This gate is pivoted to the chute 212 as indicated at 288, and has anarm 28I extending in a diagonal generally-opposite direction therefromand actuated, as the rods 216 move up and down. by connected lever 282urged downwardly by coil spring 298 acting thereon from an intermediateportion of one 01 the supporting rods 284 extending from the bracket 2'"to the chute 212. Movement is transmitted to the lever 282 toperiodically close the gate 288 by connecting rod 285 provided with aslot 288 receiving a pin 28! outstanding from the bracket 2'", and withan angle clip 290 secured to its lower end. as by a rivet 298, andactuated by engagement of the crosshead 28I therewith during part of themovement of the latter. The upper end of the connecting rod 285 isconnected by pivot pin 288 to an intermediate portion of the lever 282.The lever has one end connected to the bracket 21'! by a pivot pin 30I,and its other end provided with a slot 302 receiving a pin 303outstanding from the arm 28I of the gate 288. It will thus be seen thatduring the upper portion of the up and down movement of the rods 216,the gate is synchronously opened and closed.

The chute 212 is disposed over the bulb-preparing machine or turret 88and provided in its bottom with a funnel 304 so that as each bulb isoverturned and placed in the chute, the masking material therein isdischarged therefrom into a bulb in said turret, thereby reusing themasking material.

Operation, referring to Figures 7 to 19 In the present embodiment, theconveyor machine 8'! has 24 heads and thus the same number of indexingpositions, numbered I to 24. It is desirably set for index every 8seconds. Because of the connection of the bulb-preparing machine orturret 88 thereto, a bulb on this turret is also moved from one positionto the next every 8 seconds. The coating operation should be startedwith a supply of washed and dried bulbs, each containing a measuredquantity of the masking material. At least 24 bulbs so provided and anumber of extras should be on hand before ,starting. The bulb-preparingturret 88 should be loaded with a bulb in each position, and after.

each bulb is twirled to properly distribute the masking material, it isby hand moved to the coating machine 81. We will now follow theoperation' of a bulb from when it is first loaded on the machine to itsdischarge therefrom.

Two operators are employed, number 1 to insert the specular material,such as aluminum foil 09, in the refractory metal heating coil 8| andthe prepared bulb in the head, and number 2 to prepare the bulbs for theturret 88 and receive the aluminized bulbs. After placing the foil 89and 14 removing a bulb from the preparing turret", after the maskingmaterial has been properly dis tributed therein, it is placed in a headI04, at position 23 or 24 of the machine, the assembly of such a bulb ina head being shown diagrammatically in Figure 8. The suction at theloading position holds the bulb I55 in place. The antileakage softrubber mouthpiece or connector 2I3 serves to insure against leakagebetween the bulb and head, and the vacuum connection is made by havingthe corresponding preliminary pinch valve 2 open. The bulb travels stepby step to position 4, while being preliminarily exhausted.

At position I, if the radioor high-frequency treatment is beingemployed, it is surrounded by the high-frequency coil 285 energized soas to ionize the gas therein and facilitate evacuation. Thishigh-frequency treatment also has other desirable effects, as describedin connection with the first embodiment. The treatment may be repeatedat position 5. After the bulb arrives at position I, a change over fromthe preliminary evacuation to a final evacuation at position 8 iseffected. That is, the corresponding outer valve 2I4 is closed, whilethe corresponding inner valve 2I5 is opened, by the roller cams 235 and238, respectively. Because of the machine operating counter-clockwise,and the inner valve for each head being thus somewhat in advance of theouter valve for said head, and inasmuch as the cams 235 and 235 are onthe same radiusat position 1, the opening lever 226 of the valve 2.I5 isengaged before the closing lever 22! of the valve 2I4. As shown inFigure 12, said levers are, when the valve H5 is closed and the valve2I4 open, on approximately the same radius, so that because of thedifference in the throw of the lever 2 as compared with that of thelever 226, there is a connection to the final-vacuum system eifectedalmost simultaneously with, but a very small interval of time after, aclosing of the preliminary evacuating line.

The bulb then passes through positions 8 to I5, inclusive, and finallyreaches position I18, where the enclosed filament 9I is given a moderateelectrical energization so that the aluminum foil, or other specularmaterial 89 therein, is barely melted without appreciable vaporizationor other losses therefrom. At the next position IT, a higher electricalenergization is given to the coil 8|, or one to vaporize the aluminum orother specular material therefrom. thereby completing the coatingoperation. Position I8 is a standby flashing position which isordinarily used for cooling. Positions I9, 20, and 2| are also employedfor cooling. Between position H and po sition 22, the final vacuum valve2I5 is closed by the cam 225 and the preliminary vacuum valve 2 openedby the cam 234, as represented in Figures 10 and 11, to by virtue of theconstruction of the valve I03 at this point, break the vacuum; allowingair to come into the bulb through the pipe 284.

The breaking of the vacuum in the bulb allows it to drop the distancerepresented by the arrow 305 in Figure 15, onto the bulb holder 213,which shortly thereafter descends to the dotted position illustrated inFigure 15. This action overturns the bulb I55 onto the chute 212, whereit is momentarily stopped by the gate 288, while the masking materialtherein is discharged through funnel 304 into a bulb I 55 immediatelytherebelow, to thereby fill it with the desired quantity of maskingmaterial. By virtue of this operation, it is unnecessary to have a'great quantity of bulbs filled with masking material, or

" moved periodically and cleaned.

any great amount of masking material for the purpose. It is, however,desirable to periodically clean the masking material by sieving toremove contaminations due to the operation of the machine. Prior to thenext bulb reaching the unloading position, the gate 288 is loweredallowing the bulb under consideration to slide down the chute 212 to bereceived by an operator.

In order to insure the desired results, the machine should be keptreasonabl clean of masking material, dirt, and oil, at all times. Theguards 305 which are desirably employed around the path of the bulb toprotect the operators, and which may be formed of cellulose acetate orother similar transparent material, are desirably re- The bearingsurfaces and cams should also be kept reasonably clean and lubricated.The pumps, of course, should be kept in good condition and the degree ofvacuum during operation may be indicated by a Pirani gage (not shown).The rubber mouthpieces 2l3 of the heads I04 may be cleansed by means ofa clean lintless cloth soaked in acetone, and then wiped dry with aclean lintless cloth.

Although preferred embodiments of my invention have been disclosed, itwill be understood that modifications may be made within the spirit andscope of the appended claims.

I claim:

1. Apparatus for coating predetermined portions of' the inner surfacesof open-necked glass bulbs, comprising means for holding said bulbs withtheir open necks upward and containing granular masking material in thebottoms thereof, means comprising anti-leakage mouthpieces connectablewith bulbs through their open necks and supported refractory means whichthen depend through said necks for holding and heating said coatingmaterial, for connecting said open necks to exhausting means forproducing a vacuum in said bulbs, and at the same time positioning saidholding and heating means in said bulbs while surrounding material withwh ch the bulbs are to be coated, means for energizing said refractorymeans to flash the material on said bulbs, and means for then breakingthe vacuum to allow for removal of said bulbs from the machine.

2. Apparatus for coating predetermined portions of the inner surfaces ofopen-necked glass bulbs, comprising means for holding said bulbs, meanscomprising a chamber opening downwardly and terminating in a soft rubbermouthpiece and electrodes depending in said chamber through saidmouthpiece and supporting means for holding and heating said coatingmaterial, for connecdng said Open necks to exhausting means forproducing a vacuum in said bulbs, and at the same time positioning saidholding and heating means in said bulbs and surrounding material withwhich the bulbs are to be coated, means for energizing said electrodesto flash the material on said bulbs, and means for then breaking thevacuum to allow for removal of said bulbs from the machine.

3. Apparatus for coating with specular material predetermined portionsof the inner surface of open-necked glass bulbs, comprising a chamberopening downwardl and terminating in a soft rubber mouthpiece,electrodes depending in said chamber through said mouthpiece andsupporting means for holding and heating said coating material, avertically movable support for a bulb, means for operating said supportL cause it to raise or lower a bulb from said chamber, so that its neckenters said chamber and the electrodes enter said neck when raised,whereby the soft rubber mouthpiece engages said bulb below said neck toeffect a vacuum-tight seal, means for exhausting said chamber in orderto-remove the air from said bulb, means for energizing said heatingmeans to flash the coating material onto said supported bulb, and meansfor breaking the vacuum to said chamber to release the bulb.

4. Apparatus for coating predetermined portions only of the innersurfaces of open-necked bulbs, comprising a rotary conveyor, means forrotating said conveyor step by step and indexing it between each step ofits rotation, a plurality of exhaust heads on said conveyor, eachcomprising a chamber opening downwardly, termimating in an anti-leakagemouthpiece engageable with a bulb around its neck, and formed with leadsto support a coil for holding bulb-coating material, a vacuum valveassociated with said conveyor, vacuum lines from said valve to saidheads, one line to each head being for preliminary exhaust and the otherfor final exhaust, means in the final exhaust line between said valveand each head for improving the vacuum effected, means at one positionon said conveyor for automatically switching over from the preliminaryto the final vacuum system, means at another position for subjecting acoil in a head to energization to barel melt bulb-coating materialenclosed therein, means at the next succeeding position to flash saidcoating material from said coil onto the bulb, and a bulb holder at asucceeding position for after cooling and breaking the vacuum, receivingsaid bulb, a discharge chute.

5. Apparatus for coating predetermined portions of the inner surfaces ofopen-necked glass bulbs, comprising a turret on which a plurality ofsaid bulbs holding granula masking material may be disposed with theiropen necks upward, a rotatable support on said turret underlying eachbulb, means for indexing said turret to move each bulb from one positionto another, means in one position for twirling the underlying support soas to distribute said masking material in said bulb to a predeterminedlevel, a ro.ary conveyor portion of a coating machine adjacent saidturret, means for rotating said conveyor portion step by step andindexing it between each step of its rotation, a plurality of exhaustheads on said conveyor, each comprising a chamber opening downwardly,terminating in an anti-leakage mouthpiece engageable with a bulb aroundits neck, and formed with leads to support a coil for holdingbulb-coating material, a vacuum valve associated with said conveyor,vacuum lines from said valve to said heads, one line to each head beingfor preliminary exhaust and the other for final exhaust, means in thefinal exhaust line between-said valve and each head for improving thevacuum efiected, means adjacent said conveyor for at a given indexedposition, subjecting each bulb in its head to high-frequency treatment,means at another position for au omatically switching over from thepreliminar to the final vacuum system, means at still another positionfor subjecting a coil in a head to energlzation to barely meltbulb-coaing material enclosed therein, means at the next succeedingposition to flash said coating material from said coil onto the portionof the bulb not covered by said masking material, means at 'a succeedingposition for, after cooling, breaking the vacuum 17 to said bulb,allowing it to drop onto a holder, lowering said holder, and tippingsaid bulb onto a discharge chute, where it first pours the containedmasking material into an empty bulb held on said turret.

6. Apparatus for coating with specular metal predetermined portions ofthe inner surface of open-necked glass bulbs, comprising a chamberopening downwardly and terminating in a soft rubber mouthpiece, leadsdepending in said chamber through said mouthpiece and supporting a coilof tungsten for holding and heating a small quantity of said metal, avertically movable support for a bulb, means for lowering said bulb fromsaid chamber, or raising said bulb to said chamber so that its neckenters said chamber and the leads enter said neck, whereby the softrubber mouthpiece engages said bulb below said neck to effect avacuum-tight seal, means for exhausting said chamber-and bulb, and meansfor energizing said coil to flash the metal onto said supported bulb.

7. Apparatus for coating predetermined portions of the inner surfaces ofopen-necked bulbs, comprising a rotary conveyor, means for rotating saidconveyor step by step and indexing it between each step of its rotation,a plurality of exhaust heads on said conveyor, each com rising a chamberopening downwardly, terminating in an anti-leakage mouthpiece engageablewith a bulb around its neck, and formed with leads to support a coil forholding bulb-coating material, a pinch valve associated with saidconveyor, said valve comprising a body casting, a flexible rubber vacuumhose passing therethrough, a valve plate pivoled to said body casting, aclosing lever pivoted to said body casting and having a short angularextension carrying a roller which engages the top surface of said valveplate so as to compress the rubber hose and close the aperturetherethrough, an opening lever pivoted to the body casing and having ashort extension, a pry ing member carrying a roller and pivoted to thebody member, and a connecting rod with one end pivoted to anintermediate portion of said prying member and the other end pivoted tothe end of said opening lever extension, said prying member carrying aroller engaged by the closing member when closed, whereby when saidprying member is rotated, its roller pushes up on the closing leveruntil the latter is snapped open by the resiliency of the rubber hoseacting upward on the valve plate, vacuum lines from said valve to saidheads, one line to each head being ifor preliminary exhaust and theother for final exhaust, means in the final exhaust line between saidvalve and each head for improving the vacuum effected, means at oneposition on said conveyor for automatically switching over from thepreliminary to the final vacuum system, means at another position forsubjecting a coil in a head to energization to barely melt bulb-coatingmaterial enclosed therein, means at the next succeeding position toflash said coating material from said coil onto the bulb, a bulb holderat a succeeding position for after cooling and breaking the vacuum,receiving said bulb, a discharge chute, and means for lowering saidholder and tipping said bulb onto said chute.

8. Apparatus for coating predetermined portions of the inner surfaces ofopen-necked glass bulbs, comprising a turret on which a plurality ofsaid bulbs holding granular masking material may be disposed with theiropen necks upward, a rotatable support on said turret underlying each swm 18 bulb, means for indexing said turret to move each bulb from oneposition to another, means in one position for twirling the underlyingsupport so as to distribute said masking material in said bulb to apredetermined level, a rotary conveyor portion of a coating machineadjacent said turret, means for rotating said conveyor portion step bystep and indexing it between each step of its rotation, a plurality ofexhaust heads on said conveyor, each comprising a chamber openingdownwardly, terminating in an anti-leakage mouthpiece engageable with abulb around its neck, and formed with leads to support a coil forholding bulb-coating material, a vacuum valve associated with saidconveyor, vacuum lines from said valve to said heads, one line to eachhead being for preliminary exhaust and the o.her for final exhaust,means in the final exhaust line between said valve and each head forimproving the vacuum effected, means adjacent said conveyor for at agiven indexed position, subjecting each bulb in its head tohigh-frequency treatment, means at another position for automaticallyswitching over from ,he preliminary to the final vacuum system, means atstill another position for subjecting a coil in a head to energizationto barely melt bulb-coating material enclosed therein, means at the nextsucceeding posi ion to flash said coating material from said coil ontothe portion of the bulb not covered by said masking material, and meansat a succeeding position for, after cooling, breaking the vacuum to saidbulb, allowing it to drop onto the holder of unloading mechanismcomprising a pair of vertically reciprocable rods, a verminal castingconnecting the upper ends of said rods, said holder being pivotallycarried by said terminal casting, means for reciprocating said rods insynchronism with the indexing of said coating apparatus, and means fortilting said bulb holder as the rods move downwardly, comprising astationary portion disposed between said rods and engaging a lowerportion of said bulb holder, a chu e disposed adjacent said unloadingmechanism and onto which each bulb is periodically upset and fed there.0, and a gate pivoted toalower portion of said chute so as to stop eachbulb as it first passes to said chute, and then release it move downsaid chute prior to the reception of the next bulb.

9. Apparatus for coating predetermined portions of the inner surfaces ofopen-necked glass bulbs, comprising a rotary conveyor, means forrotating said conveyor step by step and indexing it between each step ofits rotation, a plurality of exhaust heads on said conveyor, eachcomprising a chamber opening downwardly, terminating in an anti-leakagemouthpiece engageable with a bulb around its neck, and formed with leadsto support a coil for holding bulb-coating material, a vacuum valveassociated with said conveyor, vacuum lines from aid valve to saidheads, one line to each head being for preliminary exhaust and the otherfor final exhaust, means in the final exhaust line between said valveand each head for improving the vacuum eilected, means adjacent saidconveyor for at a given indexed position, subjecting each bulb in itshead to high-frequency treatment, means at another position foautomatically switching over from the preliminary to the final vacuumsystem, means at still another position for subjecting a coil in a headto energization to barely melt bulb-coating material enclosed therein,means at the next succeeding position to flash said coating 19 materialfrom said coil onto the bulb, means at a succeeding position for, aftercooling, breaking the vacuum to said bulb, allowing it to drop onto aholder, lowering said holder, and tipping said bulb onto a dischargechute.

10. Apparatus for coating predetermined portions of the inner surfacesof open-necked glass bulbs, comprising means for preparing such bulbsfor coating said predetermined portions thereof, said means comprising arotatable turret on which a plurality of said bulbs may be disposed in acircle about the turret axis of rotation with their open necks upward,an individually rotatable support on said turret underlying each bulb, arotary conveyor portion of a coating machine with devices adapted forevacuation and deposition of coating material on said bulbs, disposed ina circle about the conveyor axis of rotation for receiving a pluralityof said bulbs holding granular masking material so spaced from saidturret axis that, at a point of near tangency between said circles, abulb on the conveyor portion may be upended to transfer containedmasking material therefrom to an adjacent bulb on said turret, means forsimultaneously rotating said conveyor portion and said turret step bystep from one position to the next, and means at one position on saidturret for twirling a rotatable bulb support sufliciently fast todisLribute granular material in the supported bulb to a predeterminedlevel, preparatory for transfer to an adjacent evacuating and coatingdevice of said rotary conveyor.

11. Apparatus for coating predetermined portions of the inner surfacesof open-necked glass bulbs, comprising a rotatable turret on which aplurality of said bulbs may be disposed in a circle about the turretaxis of rotations with their open necks upward, an individuallyrotatable support on said turret underlying each bulb, a rotary conveyorportion of a coating machine with heads disposed in a circle about theconveyor axis of rotation for receiving a plurality of said bulbsholding granular masking material so spaced from said turret axis that,at a point of near tangency between said circles, a bulb on the conveyorportion may be upended to transfer contained masking material therefromto an adjacent bulb on said turret, means for simultaneously rotatingsaid conveyor portion and said turret step by step from one position tothe next, means at one position on said turret for twirling a rotatablebulb support sufliciently fast to distribute such granular maskingmaterial in the supported bulb to a predetermined level, means for thenholding said bulbs with their open necks upward and containing thedistributed masking material in the bottoms thereof for transfer to anadjacent head of said rotar conveyor, whereby they are successivelyconnected to exhausting means for producing a vacuum therein, means onsaid heads for, when said bulbs are connected thereto, positioningheating means therein surrounding material with which the bulbs are tobe coated, means for energizing said heating means to flash the coatingmaterial on said bulbs, means for then breaking the vacuum to removesaid bulbs from the machine, and means for then upending said bulbs oneby one to transfer the granular masking material therefrom to an emptybulb on said turret.

JAMES H. GREEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

